In today's wireless communication networks, user devices such as electronic book readers, cellular telephones, personal digital assistants (PDAs), portable media players, tablet computers, and netbooks use technologies like Global System for Mobile Communications (GSM or 2G), Universal Mobile Telecommunications System (UMTS or 3G), or more recent 3GPP Long Term Evaluation (LTE or 4G), Code Division Multiple Access (CDMA), or World Interoperability for Microwave Access (WiMax) for wireless communication. Data from user applications on these wireless user devices is sent over-the-air to a base station using data radio bearers (DRBs). Using DRBs, data from different user applications on the user device passes through different protocol layers, such as Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, and Media Access Control (MAC) layer.
Data download and upload on any particular DRB is governed by a defined quality of service (QoS) between the network and the user device. This QoS is established by the network, meaning that the network provides for a guaranteed data rate, packet delay budget, and acceptable packet loss rate for the particular DRB of the user device.
When an application is started on a user device, the network providing the wireless communication for the user device will either, depending on the QoS required for the application, establish a new DRB on the user device or request the user device to share an existing DRB set up on the user device. In either case (new DRB or existing DRB), once the network configures the DRB with a given priority, typically there is no way for applications on the user device to utilize any other priority while data is passing through the protocol layers of the network interface of the user device. This can result in data from any one application overwhelming the queues at the PDCP, RLC, MAC and PHY layers in the DRB, and slowing down data from other applications without a way to prioritize data from one application over another.
Consider an example of a portable wireless device that is simultaneously using applications such as a video upload session, an e-book session, and various web browser sessions. With existing implementations of wireless technologies, all packets from the above user device applications will be sent over-the-air on DRBs with the same priority. In other words, the DRBs do not distinguish priority based on the source application of the data packet. As a result, any one application can overwhelm the queues at any of the protocol layers, and slow down or starve data from other applications. For example, the video upload session may be sending and receiving video data packets, while the web browser session is sending and receiving simple text data. In this example scenario, if the packets are sent over the same DRB (as they are in existing standards), then these packets will not be differentiated in terms of priority and the video upload session packets will overwhelm the DRB channel and ultimately slow down transmission for the simple text data packets.
LTE technology currently supports data prioritization based on the Quality Control Indicator (QCI) at the application level and prioritization at the logical channel level in the MAC layer. However, as a real-time use case, when specific application data is high priority in nature, but its QCI is low priority (according to 3GPP LTE specification published QCI table), then this application's data will be transported with low priority or the same priority as any other applications' data. In effect, this higher-priority application data may still be slowed down and experience negative performance effects due to other application data clogging the DRB pipe. Moreover, the above LTE technology data prioritization scheme requires the network's help to implement this application-specific prioritization and, as a result, such implementation is not guaranteed. In addition, such a network-implemented solution requires a premium charge for this service.